Pumping means



Feb. 4, 1941. w, 35 LANCEY 2,230,717

PUMPING MEANS Filed 001:. 24, 1939 v3 Sheets-Sheet l INVENTOR ATTORNEYSFeb. 4, 1941. w. H. DE LANCEY 2,230,717

PUMP ING MEANS Filed Oct. 24, 1959 3 Sheets-Sheet 2 INVENTOR +m ATTO R NEYS Feb. 4, 1941.

W. H. DE LANCEY PUMPING MEANS a Sheets-Shee'd 3 Filed Oct. 24, 1939 5 lhnmuna Patented Feb. 4, 1941 PATENT OFFICE PUMPING MEANS Warren H. DeLancey, Springfield, Masa, assignor to Gilbert & Barker ManufacturingCompany, West Springfield, Mass., a corporation of MassachusettsApplication October 24, 1939, Serial No. 301,013

9 Claims.

This invention relates to an improved pumping unit, which while capable013- other applications, is particularly suitable for use in oilburners.

The invention finds one advantageous use as a means for pumping the oilto an oil burner and it may, at the same time, be combined with a fanfor supplying air to the burner.

The invention has for one object the provision in an oil burner of amotor-driven, air-supplying fan and an oil-supplying pump-the latterbeing coupled to the motor solely by electromagnetic meansthearrangement being characterized in that the usual stuffing box, or othermechanical seal associated with the drive shaft of the pump, iseliminated and the oil pump with one element of the electromagneticdrive is sealed up, liquid tight, within a housing.

This arrangement has the advantage of delaying the starting of the pumpuntil the fan has been started and of stopping the pump before the fanis stopped-thereby insuring, respectively, an adequate supply of airunder proper pressure at the oil nozzle before emission of oil from thenozzle and a scavenging of all gases of-combustion from the burner aftercessation of flow of oil from the nozzle. The arrangement also avoidsthe risk of leakage through a mechanical seal and the nuisance andexpense of maintaining the same in adjustment. substantial saving in thepower necessary to drive the pump because of the elimination of theheavy friction load of the mechanical seal.

Heretofore, it has been the practice in oil burners to employ a constantspeed pump with a mechanical seal and to pump far more oil than isusually required for combustionthe excess oil being by-pas'sed aroundthe pump or returned to the supply tank. The oil is pumped at relativelyheavy pressure-say for example pounds per square inch-and if only aquarter or a fifth of the pumped oil is used at the burner as isfrequently the case, then considerable power is wasted in useless workas will be evident. Oftentimes only three gallons an hour are consumed,while the pump'works at the rate of say sixteen gallons per hour.

This invention has for an object to provide a variable speed pump fordelivering only as much oil as is requiredat the nozzle and to controlthe speed of the pump by the pressure of the pumped oil in such a mannerthat an increase in pressure of the pumped oil above a predeterminedminimum results in a reduction in speed of the pump until the pressurefalls to such minimum.

More particularly, the invention has for an ob- A further advantage is aject the provision of a slip clutch in the drive between the motor andthe oil pump and the provision of a control, responsive to the pressureof the pumped oil, for increasing the slip as such pressure increases,thereby reducing the speed of the pump until normal conditions arereestablished.

The invention also has for an object to provide an electromagnetic drivebetween the motor and pump-such drive constituting a slip clutch andenabling slippage without entailing wear and enabling also the pump andone element of said drive to be sealed up, liquid tight, within a casingand eliminating all necessity for a mechanical seal.

The invention has for a further object to provide a means responsive topressure of the pumped oil for shifting one element of theelectromagnetic drive more or less out of the field of the other to varythe torque therebetween and thereby vary the speed of the oil pump.

The invention has for a further object to provide adjacent one elementof the magnetic drive, a stationary element of magnetic material whichfunctions when the other element of the drive is shifted partially outof the field of the first element to shunt out some of the flux from thesecond element and increasethe rate of deceleration of the pump.

The invention will be disclosed with reference to the accompanyingdrawings, in which:

Fig. 1 is a sectional elevational view of a poweroperated fuel-pumpingapparatus, embodm'ng the invention;

Figs. 2, 3, and 4 are cross sectional views taken on the lines 2-2, 33and 4-4, respectively, of Fi 1;

Fig. 5 is a sectional elevational view of a modification of theinvention; and

Fig. 6 is a diagrammatical view showing the arrangement of the pumpingunit in an oil burner.

Referring to these, drawings, the invention contemplates an oil pump, ofany suitable form, power-driven by any suitable means such for exampleas an electric motor, through means in the nature of a slip clutch,which will enable slip between the driving and driven members withoutentailing wear as a consequence, and preferably also, a controlresponsive to the pressure .of the pumped oil for varying the amount ofslip between said members with the object of maintaining a constantpressure irrespective of variations in rate at which the oil is pumped.

In Fig. 1, the oil pump is mounted in a plate in Fig. l.

III between a plate II and a portion |2 of the end plate l3 of thecasing of an electric motor. The motor includes a laminated iron statorl4 having windings l5 and being suitably fixed within a casing sectionl6. Another casing section II, alined with section l6 and securedthereto in any suitable way (not shown), affords a central bearing hubl8 for rotatably supporting the shaft l9 of the motor. The rotor 20,which may be of the squirrel cage type, as indicated, is suitably fixedto shaft IS. The clutch means is interposed between thr rotor 20 and theoil pump and is located in the space which is enclosed by the companioncasing sections l1 and Hi.

The clutch means, referred to, preferably is of the electromagnetictype. In the one particular form herein shown, it includes alaminatediron member 2| fixed to an annular member 22, driven by therotor 20 and suitably fixed thereto as by the cap screws 23. Such meansalso includes a multipolar permanent magnet 24 (see Fig. 3) fixed to ashaft 25 which drives the oil pump (shown in detail in Fig. 3). Theshaft 25 is slidably keyed to the pump element--a gear 25 which itdrives--and its outer end has fixed thereto a piston 27. This piston isslidable in a cylinder 28 formed in a hub 29 on end plate l3- such hubalso affording a bearing for rotatably supporting shaft 25. The pump hasinlet and outlet ports 30 and 3|, respectively, formed in the end platel3, and the outlet port 3| is connected by a passage. 32 to the innerend of cylinder 28. Pressure of the pumped oil thus tends to push thepiston 21 to the right, as viewed in Fig. 1, and to thereby move shaft25 and carry the magnet 24 to the right.

Such movement of the shaft 25 is resisted by a spring 33 through theintermediary-of a bellcrank lever, having a depending arm 34 and alaterally-offset arm 35. The arm 35 pivotally supports a seat 36 forspring 33. This bellcrank lever is pivotally mounted on a pin 5?, havingnear one end a threaded part 38 screwed into the wall of a hollowcylindrical extension 39 of plate 53. This extension houses the spring33, bellcrank 3l--35, piston 27, and cylinder 28, and has a removablecover 40 secured by a series of cap screws 4|. The pin 5'! also has abearing at its inner end in a lug 42 on casing 39. A hexagonal head 43is provided on the outer end of pin 31, whereby it may be unscrewed andremoved whenever required. The spring 33 has a stationary seat 44threaded on the upper screwthreaded part of a shaft 45, the lower partof which is rotatably mounted in the wall of extension 39 but notordinarily axially movable therein. The seat 64 is held from turning bya web 45 on wall i2. This web engages in a notch" in seat 44. One mayturn member 45 as with a screw driver to vary the tension of spring 53.Normally, the screw is concealed by a hollow nut 47 threaded intoextension 39.

On starting up the motor, the magnetic rotor will be in the extreme lefthand position shown It will be revolved by the revolving laminated ironmember 2| because of the magnetic attraction therebetween. Initially,there will be some slip between these members because of the torquenecessary to start up the oil pump but as the latter gets under way, theslip decreases and soon the pump element 25 and the rotor 20 are turningat substantially the same speed. Then, as the pressure of the pumped oilrises high enough to overcome the pressure exerted by Spring. ,.thpiston 21 moves toward the right, drawing the permanent magnet 24 in thesame direction so that part of the magnet projects beyond the outer endface of member 2|. Thereupon the magnetic pull between the members isdecreased and the speed of the oil pump decreases. Oil will be pumped ata slower rate and the pressure will drop until it reaches the desiredpredetermined figure. With this arrangement, a constant pressure may bemaintained regardless of the rate at which the oil is pumped.

A desirable adjunct to the arrangement described is a member 50 ofmagnetic material and mounted adjacent the laminated member 2|. Thismember 50 may take the form of an annular ring of soft steel, fixed byscrews 5| to the end plate l3. As the magnetic rotor moves axially tothe right, some of the flux will enter ring 50 and the latter, beingstationary, tends by the magnetic drag to slow down the magnetic rotorand thus the oil pump. Also, the decrease in flux in member 2| isaccelerated. The use of the member 50 increases the rate of decelerationof the oil pump for any given degree of axial shifting movement of themagnetic rotor 24.

Another desirable feature is a cup 52 of nonmagnetic material whichencompasses the magnetic rotor. As shown, this cup is made of thinnon-magnetic metal (stainless steel for example) and it is held in placeby being suitably secured to member 5|. The cup renders unnecessary anyseal between the oil pump and the motor. Any leakage from the pump,along its shaft or otherwise, is caught in the cup 52. The shaft 25which not only revolves but also must slide axially, presents adifiicult sealing problem. If adequately sealed, as for example by astufiing box, rapid wear will soon cause leakage and, in any event, thestufiing box imposes a substantial load on the motor. About one-third ofthe power is used in overcoming the load of the stufiing box in averagecases. With the present arrangement, the pump can be driven with farless power and it starts up more easily because of the eliminationof theheavy resistance of the stuffing box.

Referring now to the details of the exemplary apparatus disclosed, theoil pump which may be of any suitable type, is preferably constructed asshown in Fig. 3. It includes in addition to the gear 25, an annular gear58, gotating in a cylindrical recess in plate it about an axis 55eccentric to that of shaft 25. The gear 26, turning in the direction ofthe arrow, rotates the annular gear 54 about axis 55. The inner gear hasone less tooth than the outer gear 54. The two gears present a series ofclosed pockets 56 which gradually expand in volume as the rotors turnfrom the full mesh position 5'|'to the open mesh position 58. Duringpart of the time, while these pockets are expanding in volume, theycommunicate with inlet port 30 and thus fluid is drawn into them bysuction from an inlet passage 60. Then each pocket becomes cut ofl fromport and, shortly after, moves into position where it can communicatewith outlet port 3| at a time when the pockets are decreasing in volume,whereby liquid is expressed through the port 3| and into an outletpassage 59. This pump construction is more completely disclosed in HillPatents Nos. 1,682,564 and 1,682,565, both dated Aug. 28, 1928.

The slip clutch preferably has the laminated member 2| constructed inmuch the same general manner as the squirrel cage rotor of an inductionmotor. It has a short-circuited winding made up of a plurality of copperrods 8|, extending through slots in the laminations 2|, and a pair ofannular copper rings 62the ends of each rod 6! being connected one toone ring 62 and one to the other ring 62. The magnet 2 may convenientlybe a permanent magnet made of some of the special alloy steels whichafford exceedingly high coercive force. This magnet is cast in the formshown having a plurality (six as shown) of poles arranged in a circularseries with alternate poles 63 of opposite polarity as indicated in Fig.3. I

This magnet is secured to shaft 25 in any suitable way. For example, themagnet may have cast therein a hole Blof square or other noncircularshape, to receive a head 65 of hexagonal or other circular shape. Themagnet and head 65 are assembled in a jig, by which they are positionedaccurately in proper relation, and then the space between hole 64 andhead 65 is filled with some suitable metal, such as zinc 6'! forexample. The head 55, as shown, is part of a stud 66 screwed into shaft25. The construction described is not important in itself and is merelyillustrative of one of many available ways for mounting the magnet onshaft 25.

The motor usually also drives a fan especially when the pumping unit isused in connection with an oil burner. Thus, in Fig. l, a fan rotor 68is shown as fixed by screws 88 to the shaft IQ of the motor. The rotor68 revolves inside a suitable casing 69 as indicated.

When the pumping unit is used with an oil burner, it is arranged asshown diagrammatically in Fig. 6. The motor M, such as described above,drives the oil pump 10. This pump draws in oil through an inlet passage60 and forces it through the outlet 59 into a pipe 10 and thence througha valve H and pipe 12 to the atomizing nozzle 13. This nozzle isarranged within a tube 14, connected to the outlet of the fan casing 69described. The valve 11 has the function of preventing passage of oil tothe nozzle until the oil has been placed under the desired predeterminedpressure-say for example 100 pounds per square inch.

The invention may be used, with certain advantages, without the controldevice described which shifts the magnet axially to vary the torquebetween the driving and driven elements 2! and 24; Such an arrangementis shown in Fig. 5. The motor, the mounting of its parts, theelectromagnetic transmission between the motor and oil pump, are thesame as has been described and corresponding parts have been marked withthe same reference numerals with the addition of a prime. Here, however,the oil pump Ill is mounted outside the end plate I3 which is ofsomewhat different form, and the pump shaft 25' and the magnet 24' fixedthereon are not' axially slidable. The oil inlet and outlet passages 59and 60' are located differently but function as before. The oil pump Iis, or may be, exactly the same as shown in Fig. 4 and the magnet 24 andits cooperating laminated member 2| are exactly as shown in Fig. 3.

That form of the invention shown in Fig. 5 has the advantage of adelayed starting of the oil pump and an earlier stopping of the same, asabove pointed out. Also, the construction avoids the necessity for astumng box or other equivalent form of mechanical seal. The eliminationof a seal between relatively rotatable parts is very important. Alllikelihood of leakage is avoided. The frequent care necessary tomaintain such aseal tight is avoided. Again, the heavy friction load ofthe seal is eliminated. In many oil burner pumps, this friction loadrepresents one-third of the power consumed. Much easier and quickerstarting results and actually a much smaller and less expensive drivingmotor can be used.

In the preferred form of the invention, all the advantages justenumerated are secured, with others. Thus the pump is driven by avariable speed transmission and the oil is maintained at constantpressure without pumping any more oil than is actually needed forcombustion. The rate of pumping will vary as may be necessary tomaintain the desired predetermined pressure. Actually, in the use of theinvention in connec tion with oil burners, the pump, once it has builtup-the desired pressure, will run at about uniform speed because oil isbeing consumed at a substantially uniform rate during burner operation.However, if the invention is used in such a way that the liquid isconsumed at a variable rate, the pump will operate at variable speedunder the described control.

a substantial saving in power is effected by this variable speed driveas against the pumping means heretofore employed in oil burners. Theprior practice was to use a pump of large enough capacity to suit theconditions of any installation likely to be made. In most cases, the oilwas consumed at a rate far less than that of the pump. As a commonexample, the pump has a capacity of 16 gallons per hour and about threegallons per hour is the rate of consumption. of oil by the burner. Theresult is that oil is pumped at the maximum rate and raised to thedesired predetermined pressure-usually around 100 pounds per squareinch-and two-thirds of the oil thus pumped is loy-passed around the pumpor returned to the supply tank as the case may be. Two-thirds of theenergy consumed in pumping the oil is thus wasted. With the presentinvention and under the same conditions, the pump would pump the threegallons per hour required by the burner and no more. .The use of a largecapacity pump, such as that herein referred to as being capable ofpumping 16 gallons an hours, has the advantage of enabling quickpriming. Even though the normal rate of consumption of oil is usuallysomewhere around three gallons per hour, the high capacity pump is ofgreat advantage, whenever it is necessary to pump all air out of thesystem, as after stoppage of the burner from exhaustion of oil. Oneusually opens a vent in the system somewhere on the pressure side of thepump to allow the air to escape. It is desired to rid the system of airas quickly as possible and under these conditions, the pump can and doesoperate at maximum capacity even though when pumping oil under normalconditions, the pump operates at a much lower capacity.

The invention thus offers an improved pumping unit which, while capableof general application, is especially suitable for use with oil burnersand is characterized by a substantial saving in operating rotatablemagnetic members one mechanically connected to said motor and the othermechanically connected to said pump; and a liquid-tight housing encasingsaid pump and the member connected thereto and including a nonmagneticportion extending through the space between said rotatable members.

2. In combination, a pump, a motor, driving means therebetween includingspaced-apart cooperating rotatable magnetic members one mechanicallyconnected to said motor and the other mechanically connected to saidpump, one of said members comprising a magnetized field element and theother member comprising a wound armature; and a liquid-tight housingencasing said pump and the member connected thereto and including anon-magnetic portion extending through the space between said rotatablemembers.

3. In combination, a pump, a motor, driving means therebetween includingspaced-apart cooperating rotatable magnetic members one mechanicallyconnected to said motor and the other mechanically connected to saidpump, one of said members comprising a multipolar permanent magnet andthe other a laminated-iron armature with a squirrel cage winding; and aliquid-tight housing 'encaslng said pump and the member connectedthereto and including a non-magnetic portion extending through the spacebetween said rotatable members.

4. In combination, a pump including a casing and a drive shaftprojecting therefrom, a multipolar permanent magnet fixed to said shaft,a cup of thin non-magnetic material secured to said casing and with thelatter entirely enclosing within it said shaft and magnet, a motor, anda wound inductor driven by the motor and surrounding said magnet andcup.

5. In combination, a pump having an outlet passage, a valve closing saidpassage until a predetermined pressure has been built up therein by saidpump, a motor, driving means connecting said pump and motor andincluding cooperating elements in the nature of a slip clutch, and meanscontrolling the slip between said elements and varying such slipsubstantially in direct proportion to variations in pressure of thepumped fluid above said predetermined pressure.

6. In combination, a pump, a motor, and driving means connecting thepump and motor and including cooperating rotatable elements one drivenby the motor and the other driving the pump and the one driving theother magnetically, 'said elements being relatively shiftable in thedirection of the axis of rotation of said elements, and means responsiveto the pressure of the pumped fluid for axially shifting said elements.

7. In combination, a pump, a motor, and driving means interconnectingthe pump and motor and including a magnetic field element connected todrive said pump, an armature element driven by said motor andcooperatively associated with said field element to drive the samethrough the force of magnetic attraction between said elements, astationary member of magnetic material adjacent said armature element,said field element being shiftable from a position of full cooperativeassociation with said armature to any of a plurality of positions inwhich part of its magnetic flux passes into said stationary member andis thereby shunted out of said armature element, and means responsive tothe pressure of the pumped fluid for shifting the field element.

8. In combination, a pump having an outlet passage, a valve closing saidpassage until a predetermined pressure has been built up therein by saidpump, a motor, and driving means interconnecting the pump and motor andincluding a magnetic field element connected to drive said pump,anarmature element driven by said motor and cooperatively associated withsaid field element to drive the same through the force of magneticattraction between said elements, a stationary member of magneticmaterial adjacent said armature element, said field element beingshiftable from a position of full cooperative association with saidarmature to any of a plurality of positions in which part of itsmagnetic flux passes into said stationary member and is thereby shuntedout of said armature element, and means responsive to increase in thepressure of the pumped fluid above said predetermined pressure forrelatively shifting said elements in the axial direction necessary todecrease the magnetic pull therebetween and responsive to a subsequentdecrease in such pressure of the pumped oil to relatively shift saidelements in the opposite direction.

9. In combination, a pump having an outlet passage, a valve closing saidpassage until a predetermined pressure has been built up therein by saidpump, a motor, and driving means interconnecting the pump and motor andincluding a magnetic field element connected to drive said pump, anarmature element driven by said motor and cooperatively associated withsaid field element to drive the same through the force of magneticattraction between said elements, a stationary member of magneticmaterial adjacent said armature element, said field element beingshiftable from a position of full cooperative association with saidarmature to any of a plurality of positions in which part of itsmagnetic flux passes into said stationary member and is thereby shuntedout of said armature element, and means responsive to increase inpressure of the pumped fluid above said predetermined pressure to shiftsaid field element from the first-named to some one of the second-namedositions and responsive to a subsequent-decrease in pressure of thepumped oil to shift said field element back toward its first-namedposition.

WARREN H. DE LANCEY.

